U.S. patent application number 11/216031 was filed with the patent office on 2006-02-02 for method and apparatus for producing a mosaic image.
This patent application is currently assigned to ChemImage Corporation. Invention is credited to Arjun S. Bangalore, Jason H. Neiss.
Application Number | 20060023217 11/216031 |
Document ID | / |
Family ID | 35599497 |
Filed Date | 2006-02-02 |
United States Patent
Application |
20060023217 |
Kind Code |
A1 |
Bangalore; Arjun S. ; et
al. |
February 2, 2006 |
Method and apparatus for producing a mosaic image
Abstract
The disclosure relates to method and apparatus for providing a
mosaic image based on two or more sub-images. A method according to
the disclosure includes irradiating a sample with light to thereby
produce photons from the sample and forming two or more sub-images
from the photons; the sub-images formed from photons of
substantially the same wavelength. The plurality of sub-images of
the sample can be combined in a mosaic-type formation to define an
image of the sample. Similar images of the sample at different
wavelengths can be combined to form a comprehensive mosaic image of
the sample at all wavelengths.
Inventors: |
Bangalore; Arjun S.;
(Monroeville, PA) ; Neiss; Jason H.; (Pittsburgh,
PA) |
Correspondence
Address: |
DUANE MORRIS LLP
Suite 700
1667 K Street, N.W.
Washington
DC
20006
US
|
Assignee: |
ChemImage Corporation
|
Family ID: |
35599497 |
Appl. No.: |
11/216031 |
Filed: |
September 1, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10986274 |
Nov 12, 2004 |
|
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11216031 |
Sep 1, 2005 |
|
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60575090 |
May 28, 2004 |
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Current U.S.
Class: |
356/418 |
Current CPC
Class: |
G06T 5/006 20130101;
G01J 2003/2826 20130101; G06T 5/50 20130101 |
Class at
Publication: |
356/418 |
International
Class: |
G01N 21/25 20060101
G01N021/25 |
Claims
1. A method for producing an image of an object from overlapping
sub-images where each sub-image includes plural pixels each having
an initial intensity value, comprising: (a) irradiating the object
with light to thereby produce from the object light for each of a
plurality of wavelengths; (b) producing a plurality of overlapping
sub-images of the object for each of the plurality of wavelengths;
and (c) for a first and a second of said overlapping sub-images
produced at one of said wavelengths: (i) determining an overlap
region; (ii) determining a line of fusion within said overlap
region; and (iii) stitching together said first and second
sub-images to thereby produce a stitched image.
2. The method of claim 1 further comprising the steps of: (iv)
determining if the line of fusion in the stitched image meets a
predetermined criteria for requiring correction; and (v) correcting
the stitched image if the predetermined criteria is met.
3. The method of claim 2 wherein the step of correcting the
stitched image comprises the steps of: (A) defining a window in the
stitched image which contains the line of fusion; (B) obtaining,
for one of the pixels in said window, the intensity value of a
corresponding pixel in each of the first and second sub-images; (C)
determining a weighted sum intensity value for the corresponding
pixels; and (D) replacing the intensity value of said one pixel in
said window with the weighted sum intensity value.
4. The method of claim 1 wherein the step of stitching together
said first and second sub-images comprises steps of: (A) copying
the intensity value of pixels located in said first sub-image
between an edge opposite the line of fusion and the line of fusion;
(B) copying the intensity value of pixels located in said second
sub-image between the line of fusion and an edge opposite the line
of fusion; and (C) creating a stitched image by combing the copied
intensity values from said first and second sub-images.
5. The method of claim 1 including the step of locating the object
so that the image of the object will appear registered properly in
the stitched image.
6. The method of claim 5 wherein the width of the stitched image is
less than the combined width of the first and second
sub-images.
7. A method for producing a chemical image of an object from
overlapping sub-images where each sub-image includes plural pixels
each having an initial intensity value, the method comprising the
steps of: (a) irradiating the object with light to thereby produce
from the object light for each of a plurality of wavelengths; (b)
producing a plurality of overlapping sub-images of the object for
each of the plurality of wavelengths; and (c) for a first and
second of said overlapping sub-images produced at one of said
wavelengths: (i) determining an overlap region; (ii) determining a
line of fusion within said overlap region; and (iii) stitching
together said first and second sub-images to thereby produce a
stitched chemical image.
8. The method of claim 7 further comprising the steps of: (iv)
determining if the line of fusion in the stitched chemical image
meets a predetermined criteria for requiring correction; and (v)
correcting the stitched chemical image if the predetermined
criteria is met.
9. The method of claim 8 wherein the step of correcting the
stitched chemical image comprises the steps of: (A) defining a
window in the stitched chemical image which contains the line of
fusion; (B) obtaining, for one of the pixels in said window, the
intensity value of a corresponding pixel in each of the first and
second sub-images; (C) determining a weighted sum intensity value
for the corresponding pixels; (D) replacing the intensity value of
said one pixel in said window with the weighted sum intensity
value; and (E) replacing all the pixel intensity values of the said
window with the weighted sum intensity values.
10. The method of claim 7 wherein the step of stitching together
said first and second sub-images comprises the steps of: (A)
copying the intensity value of pixels located in said first
sub-image between an edge opposite the line of fusion and the line
of fusion; (B) copying the intensity value of pixels located in
said second sub-image between the line of fusion and an edge
opposite the line of fusion; and (C) creating a stitched chemical
image by combining the copied intensity values from said first and
second sub-images.
11. The method of claim 7 including the step of locating the object
so that the chemical image of the object will appear registered in
the stitched chemical image.
12. The method of claim 11 wherein the width of the stitched
chemical image is less than the combined width of the first and
second sub-images.
13. The method of claim 7 wherein the chemical image is a Raman
image.
14. A method for producing a Raman image of an object from
overlapping sub-images where each sub-image includes plural pixels
each having an initial intensity value, the method comprising the
steps of: (a) irradiating the object with light to thereby produce
from the object Raman scattered light for each of a plurality of
wavelengths; (b) producing a plurality of overlapping sub-images of
the object for each of the plurality of wavelengths; and (c) for a
first and a second of said overlapping sub-images produced at one
of said wavelengths: (i) determining an overlap region; (ii)
determining a line of fusion within said overlap region; (iii)
stitching together said first and second sub-images to thereby
produce a stitched Raman image by performing the steps of: (A)
copying the intensity value of pixels located in said first
sub-image between an edge opposite the line of fusion and the line
of fusion; (B) copying the intensity value of pixels located in
said second sub-image between the line of fusion and an edge
opposite the line of fusion; and (C) creating a stitched chemical
image by combining the copied intensity values from said first and
second sub-images; (iv) determining if the line of fusion in the
stitched Raman image meets a predetermined criteria for requiring
correction; and (v) correcting the stitched Raman image if the
predetermined criteria is met, by performing the steps of: (A)
defining a window in the stitched Raman image which contains the
line of fusion; (B) obtaining, for one of the pixels in said
window, the intensity value of a corresponding pixel in each of the
first and second sub-images; (C) determining a weighted sum
intensity value for the corresponding pixels; and (D) replacing the
intensity value of said one pixel in said window with the weighted
sum intensity value.
15. The method of claim 14 including the step of locating the
object so that the Raman image of the object will appear
substantially in the center of the stitched Raman image.
16. The method of claim 15 wherein the width of the stitched Raman
image is less than the combined width of the first and second
sub-images.
17. The method of claim 15 further comprising the step of: (E)
replacing all the pixel intensity value of the said window with the
weighted sum intensity values.
18. An imaging spectroscope for producing an image of an object
from overlapping sub-images where each sub-image includes plural
pixels each having an initial intensity value, the spectroscope
comprising: (a) a photon source for irradiating the object with
light to thereby produce from the object light for each of a
plurality of wavelengths; (b) a photon detector for producing a
plurality of overlapping sub-images of the object for each of the
plurality of wavelengths; and (c) a processor programmed to perform
a plurality of executable instructions, the instructions
comprising: (i) determining an overlap region for a first and a
second of said overlapping sub-images produced at one of said
wavelengths; (ii) determining a line of fusion within said overlap
region; and (iii) stitching together said first and second
sub-images to thereby produce a stitched image.
19. The spectroscope of claim 18 wherein said processor is further
programmed to execute the instructions of: (iv) determining if the
line of fusion in the stitched image meets a predetermined criteria
for requiring correction; and (v) correcting the stitched image if
the predetermined criteria is met.
20. The imaging spectroscope of claim 19 wherein said processor is
further programmed so that the instruction of correcting the
stitched image comprises the instructions of: (A) defining a window
in the stitched image which contains the line of fusion; (B)
obtaining, for one of the pixels in said window, the intensity
value of a corresponding pixel in each of the first and second
sub-images; (C) determining a weighted sum intensity value for the
corresponding pixels; (D) replacing the intensity value of said one
pixel in said window with the weighted sum intensity value. (E)
Replacing the pixel intensity value of the said window with the
weighted sum intensity values.
21. The imaging spectroscope of claim 20 wherein the window is
approximately 30 pixels wide.
22. The imaging spectroscope of claim 18 wherein said processor is
further programmed so that the instruction of stitching together
said first and second sub-images comprises the instructions of: (A)
copying the intensity value of pixels located in said first
sub-image between an edge opposite the line of fusion and the line
of fusion; (B) copying the intensity value of pixels located in
said second sub-image between the line of fusion and an edge
opposite the line of fusion; and (C) creating a stitched image by
combining the copied intensity values from said first and second
sub-images.
23. The imaging spectroscope of claim 18 wherein said light
produced from the object includes one or more of fluorescence
light, reflected light, refracted light, transmitted light, and
scattered light.
24. The imaging spectroscope of claim 18 wherein said image is a
chemical image and said stitched image is a stitched chemical
image.
25. The imaging spectroscope of claim 18 wherein said image is a
Raman image and said stitched image is a stitched Raman image.
26. A imaging spectroscope for producing a Raman image of an object
from overlapping sub-images where each sub-image includes plural
pixels each having an initial intensity value, the method
comprising the steps of: (a) a photon source for irradiating the
object with light to thereby produce from the object Raman
scattered light for each of a plurality of wavelengths; (b) a
photon detector for producing a plurality of overlapping sub-images
of the object for each of the plurality of wavelengths; and (c) a
processor programmed to perform a plurality of executable
instructions, the instructions comprising: (i) determining an
overlap region for a first and a second of said overlapping
sub-images produced at one of said wavelengths; (ii) determining a
line of fusion within said overlap region; (iii) stitching together
said first and second sub-images to thereby produce a stitched
Raman image by performing the steps of: (A) copying the intensity
value of pixels located in said first sub-image between an edge
opposite the line of fusion and the line of fusion; (B) copying the
intensity value of pixels located in said second sub-image between
the line of fusion and an edge opposite the line of fusion; and (C)
creating a stitched chemical image by combining the copied
intensity values from said first and second sub-images; (iv)
determining if the line of fusion in the stitched Raman image meets
a predetermined criteria for requiring correction; and (v)
correcting the stitched Raman image if the predetermined criteria
is met, by performing steps of: (A) defining a window in the
stitched Raman image which contains the line of fusion; (B)
obtaining, for one of the pixels in said window, the intensity
value of a corresponding pixel in each of the first and second
sub-images; (C) determining a weighted sum intensity value for the
corresponding pixels; and (D) replacing the intensity value of said
one pixel in said window with the weighted sum intensity value.
27. The method of claim 26 including the step of locating the
object so that the Raman image of the object will appear
substantially properly registered the stitched Raman image.
28. The method of claim 27 wherein the width of the stitched Raman
image is less than the combined width of the first and second
sub-images.
29. The method of claim 26 further comprising the step of: (E)
replacing all the pixel intensity value of said window with the
weighted sum intensity values.
Description
[0001] The instant application relates to Provisional Application
No. 60/575,090 filed May 28, 2004 and application Ser. No.
10/812,233 filed Mar. 29, 2004. The specification of each
application is incorporated herein in its entirety.
BACKGROUND
[0002] Spectroscopic imaging combines digital imaging and molecular
spectroscopy techniques, which can include Raman scattering,
fluorescence, photoluminescence, ultraviolet, visible and infrared
absorption spectroscopies. When applied to the chemical analysis of
materials, spectroscopic imaging is commonly referred to as
chemical imaging. Instruments for performing spectroscopic (i.e.
chemical) imaging typically comprise image gathering optics, focal
plane array imaging detectors and imaging spectrometers.
[0003] In general, the sample size determines the choice of image
gathering optic. For example, a microscope is typically employed
for the analysis of sub micron to millimeter spatial dimension
samples. For larger objects, in the range of millimeter to meter
dimensions, macro lens optics are appropriate. For samples located
within relatively inaccessible environments, flexible fiberscope or
rigid borescopes can be employed. For very large scale objects,
such as planetary objects, telescopes are appropriate image
gathering optics.
[0004] For detection of images formed by the various optical
systems, two-dimensional, imaging focal plane array (FPA) detectors
are typically employed. The choice of FPA detector is governed by
the spectroscopic technique employed to characterize the sample of
interest. For example, silicon (Si) charge-coupled device (CCD)
detectors or CMOS detectors are typically employed with visible,
fluorescence and Raman spectroscopic imaging systems, while indium
gallium arsenide (InGaAs) FPA detectors are typically employed with
near-infrared spectroscopic imaging systems.
[0005] Spectroscopic imaging can be implemented by one of two
methods. First, a point-source illumination can be provided on the
sample to measure the spectra at each point of the illuminated
area. Second, spectra can be collected over the an entire area
simultaneously using an active optical imaging filter such as AOTF
or LCTF. Here, the organic material in the optical filters are
actively aligned by applied voltages to produce the desired
bandpass and transmission function. Thus, spectral images of a
sample are often require accumulation and combination of images of
a sample at a number of wavelengths.
[0006] The ability to provide a spectral image of a sample is often
limited by the field of view of the spectral imaging device. For
microscopic imaging the field of view is deliberately made small in
order to capture the details of the sample. Because the field of
view is limited to a small region of the sample, several such
images have to be combined in a mosaic to define the entire sample.
Conventional technologies allow image stitching to obtain a
panoramic view of individual sequential frames of a scenery in the
X-direction. Conventional technologies are inoperable with
n-dimensional images or high resolution chemical imaging formed
from combination of images at different wavelengths.
SUMMARY OF THE DISCLOSURE
[0007] In one embodiment, the disclosure relates to a method for
producing an image of an object from overlapping sub-images where
each sub-image includes plural pixels each having an initial
intensity value, comprising irradiating the object with light to
thereby produce from the object scattered light for each of a
plurality of wavelengths; producing a plurality of overlapping
sub-images of the object for each of the plurality of wavelengths;
and for a first and a second of said overlapping sub-images
produced at one of said wavelengths: (i) determining an overlap
region; (ii) determining a line of fusion within said overlap
region; and (iii) stitching together said first and second
sub-images to thereby produce a stitched image.
[0008] In another embodiment the disclosure relates to a method for
producing a chemical image of an object from overlapping sub-images
where each sub-image includes plural pixels each having an initial
intensity value, the method comprising the steps of (a) irradiating
the object with light to thereby produce from the object scattered
light for each of a plurality of wavelengths; (b) producing a
plurality of overlapping sub-images of the object for each of the
plurality of wavelengths; and (c) for a first and a second of said
overlapping sub-images produced at one of said wavelengths: (i)
determining an overlap region; (ii) determining a line of fusion
within said overlap region; and (iii) stitching together said first
and second sub-images to thereby produce a stitched chemical
image.
[0009] In still another embodiment, the disclosure relates to a
method for producing a Raman image of an object from overlapping
sub-images where each sub-image includes plural pixels each having
an initial intensity value, the method comprising the steps of: (a)
irradiating the object with light to thereby produce from the
object Raman scattered light for each of a plurality of
wavelengths; (b) producing a plurality of overlapping sub-images of
the object for each of the plurality of wavelengths; and (c) for a
first and a second of said overlapping sub-images produced at one
of said wavelengths: (i) determining an overlap region; (ii)
determining a line of fusion within said overlap region; (iii)
stitching together said first and second sub-images to thereby
produce a stitched Raman image by performing the steps of: (A)
copying the intensity value of pixels located in said first
sub-image between an edge opposite the line of fusion and the line
of fusion; (B) copying the intensity value of pixels located in
said second sub-image between the line of fusion and an edge
opposite the line of fusion; and (C) creating a stitched chemical
image by combining the copied intensity values from said first and
second sub-images; (iv) determining if the line of fusion in the
stitched Raman image meets a predetermined criteria for requiring
correction; and (v) correcting the stitched Raman image if the
predetermined criteria is met, by performing the steps of: (A)
defining a window in the stitched Raman image which contains the
line of fusion; (B) obtaining, for one of the pixels in said
window, the intensity value of a corresponding pixel in each of the
first and second sub-images; (C) determining a weighted sum
intensity value for the corresponding pixels; and (D) replacing the
intensity value of said one pixel in said window with the weighted
sum intensity value.
[0010] Another embodiment the of the disclosure relates to a
spectroscope for producing an image of an object from overlapping
sub-images where each sub-image includes plural pixels each having
an initial intensity value, the spectroscope comprising (a) a
photon source for irradiating the object with light to thereby
produce from the object scattered light for each of a plurality of
wavelengths; (b) a photon detector for producing a plurality of
overlapping sub-images of the object for each of the plurality of
wavelengths; and (c) a processor programmed to perform a plurality
of executable instructions, the instructions comprising: (i)
determining an overlap region for a first and a second of said
overlapping sub-images produced at one of said wavelengths; (ii)
determining a line of fusion within said overlap region; and (iii)
stitching together said first and second sub-images to thereby
produce a stitched image.
[0011] A spectroscope according to one embodiment of the disclosure
comprises (a) a photon source for irradiating the object with light
to thereby produce from the object Raman scattered light for each
of a plurality of wavelengths; (b) a photon detector for producing
a plurality of overlapping sub-images of the object for each of the
plurality of wavelengths; and (c) a processor programmed to perform
a plurality of executable instructions, the instructions
comprising: (i) determining an overlap region for a first and a
second of said overlapping sub-images produced at one of said
wavelengths; (ii) determining a line of fusion within said overlap
region; (iii) stitching together said first and second sub-images
to thereby produce a stitched Raman image by performing the steps
of: (A) copying the intensity value of pixels located in said first
sub-image between an edge opposite the line of fusion and the line
of fusion; (B) copying the intensity value of pixels located in
said second sub-image between the line of fusion and an edge
opposite the line of fusion; and (C) creating a stitched chemical
image by combining the copied intensity values from said first and
second sub-images; (iv) determining if the line of fusion in the
stitched Raman image meets a predetermined criteria for requiring
correction; and (v) correcting the stitched Raman image if the
predetermined criteria is met, by performing the steps of: (A)
defining a window in the stitched Raman image which contains the
line of fusion; (B) obtaining, for one of the pixels in said
window, the intensity value of a corresponding pixel in each of the
first and second sub-images; (C) determining a weighted sum
intensity value for the corresponding pixels; and (D) replacing the
intensity value of said one pixel in said window with the weighted
sum intensity value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic illustration of a mosaic image of a
sample;
[0013] FIG. 2 is a schematic representation of spectral image
formation of a sample;
[0014] FIG. 3 shows a method for stitching two sub-images according
to one embodiment of the disclosure; and
[0015] FIG. 4 schematically illustrates the process of forming a
mosaic image of a sample from two sub-images according to one
embodiment of the disclosure.
DETAILED DESCRIPTION
[0016] The embodiments disclosed herein relate to method and
apparatus for producing a mosaic image from several frames or
sub-images. The embodiments disclosed herein are suitable for use,
among others, in forming a chemical image of a sample.
[0017] FIG. 1 is a schematic illustration of a mosaic image of a
sample. In FIG. 1, the field of view captures sub-images 110,
120,130 and 140. A combination of sub-images 100, 120, 130 and 140
forms image 100. When applied to chemical imaging, each sub-image
110, 120, 130 and 140 can be collected at one wavelength;
alternatively, they can be images at any one of the plurality of
wavelengths at which sub-images can be collected. The sub-images
may have about 5% spatial overlap. The overlap, if not removed, can
cause distortion in the final mosaic image. When applied to
chemical imaging methods such as Raman, fluorescence, etc., the
overlap can cause serious misrepresentation or mischaracterization
of the sample.
[0018] A first step in forming a mosaic image is to identify a
region (or a window) that contains one or more common features in
the sub-images. Next, the sub-images having the common feature are
arranged next to each other as a montage or a mosaic (see FIG. 1.)
In forming a montage the goal is forming a mosaic image with little
or no spatial overlap among frames.
[0019] FIG. 2 is a schematic representation of spectral image
formation of a sample. Referring to FIG. 2, each of image 1 and
image 2 is shown to be a combination of sub-images taken at
different wavelengths .lamda.. By adjoining sub-images having the
same wavelength, a mosaic image can be formed. By combining the
mosaic images of the sample having different wavelengths, a
complete image can be formed.
[0020] In method according to one embodiment, a spectral image of a
sample is formed from overlapping sub-images, collected by
irradiating the object with light of varying or constant
wavelength. The photons reaching the sample are scattered by the
sample, thereby forming scattered photons having different
wavelengths than the incident photons. In one embodiment, the
disclosure relates to forming a plurality of overlapping sub-images
of the sample for each of the plurality of wavelengths. The image
is compiled from several sub-images where each sub-image has an a
similar wavelength. That is, a first and a second sub-image having
the same wavelength are adjoined based on a common reference point
to form an image. The process of adjoining the first and the second
sub-images is interchangeably referred to as stitching.
[0021] Once formed, the image can be inspected for overlaps.
Overlap estimation can be implemented by visual inspection or by
conventionally-available software. Once the overlapping region is
identified, a line of fusion (i.e., the stitch line) within the
overlapping window can be identified. The line of fusion may
include one or more feature common to both sub-images. To stitch
the first and the second sub-images together according to one
embodiment of the disclosure, a line of fusion is identified in the
overlapping region and pixel intensity values to either side of the
line of fusion are obtained to form an image.
[0022] FIG. 3 shows a method for stitching two sub-images according
to one embodiment of the disclosure. In the exemplary embodiment of
FIG. 3, where two sub-images are combined to form an image, the
intensity value of each pixel located in the first sub-image
between an edge opposite the line of fusion and the line of fusion
is used. In one embodiment, the edge opposite the line of fusion
for each sub-image is the non-overlapping edge. Specifically, sub
images 310 and 320 are formed independently of each other. To
combine sub-images, a common reference point can be identified in
each sub-image and based thereon the sub-images can be adjoined to
form a mosaic image. Next, overlapping region can be estimated
visually or by software inspection. Line of fusion 330 can then be
identified common to and between sub-images 310 and 320.
[0023] According to one embodiment of the disclosure, a mosaic
image 350 is formed by copying pixels from each of the sub-images.
To this end, pixels to the left of stitch line 330 along in
sub-image 310 and pixels to the right of stitch line 330 in
sub-image 320 are copied onto image 350 (FIG. 3B). For example,
pixel 311 from sub-image 310 is copied to the left of stitch line
330 and pixel 321 from sub-image 320 is copied to the right of
stitch line 330 of mosaic image 350 (FIG. 3B). Once the pixels are
copied, a determination can be made as to whether additional
correction is required. To this end mosaic image 350 or a portion
thereof can be assessed against a predefined threshold to determine
whether further correction is required.
[0024] If correction is deemed required, a window containing at
least a portion of stitch line 330 can be defined. In FIG. 3B,
window 340 containing stitch line 330 is shown. Within the window a
first and a second exemplary pixels are selected such that each
pixel falls on one side of stitch line 330. Referring to FIG. 3B,
first exemplary pixel 313 and second exemplary pixel 323 are
selected and the intensity value of each exemplary pixel is
determined. Next, a weighted-sum intensity value is determined as a
function of the intensity values of exemplary pixels 313 and 323
from the original sub-images 310 and 320. Finally, to correct the
stitched image, the intensity value of each pixel in window 340 is
replaced with the weighted-sum intensity value. While in the
illustrative example of FIG. 3, the intensity of window 340 is
identified and replaced with a weighted-sum intensity, the scope of
the disclosure is not limited thereto.
[0025] The embodiments of the disclosure are particularly suitable
for spectral imaging of a sample. As stated, obtaining a refined
image of the entire sample may require a compilation of several
sub-images. To produce a chemical image of an object from
overlapping sub-images in accordance with one embodiment of the
disclosure, the sample is illuminated by photons. The illuminating
photons can have different wavelengths consistent with the intended
form of spectroscopy. Once illuminated the sample scatters photons
of different wavelength. Forming a spectroscopic image of the
sample may require combining two or more sub-images having
substantially identical wavelengths as a mosaic.
[0026] FIG. 4 schematically illustrates the process of forming a
mosaic image of a sample from two sub-images according to one
embodiment of the disclosure. In FIG. 4, sub-images 410 and 420
have been collected from a sample. Sub-images 410 and 420 can
define Raman, Fluorescence, or other forms of chemical imaging.
Moreover, the sub-images can define photons scattered from the
sample at substantially the same wavelength. As can be seen from
FIG. 4, sub-images 410 and 420 comprise an overlapping region 415.
As before, the overlapping region can be identified through visual
inspection or by software. Once an overlapping region in each of
the sub-images has been identified, a line of fusion within each
overlapping window 415 can be defined. An exemplary line of fusion
425 is shown in each of sub-images 410 and 420. By adjoining
sub-images 410 and 420 along fusion line 415, mosaic image 430 can
be formed. For reference, fusion line 415 as well as overlapping
region 425 are also identified at image 430.
[0027] Once mosaic image 430 is formed, the image can be inspected
for quality. The inspection can assess whether the line of fusion
in the stitched image meets a predetermined criteria for requiring
correction. If the overall intensity values at and on either side
the line of fusion inside the window 415 is approximately similar,
then the mosaic image would appear seamless. If not, there will be
discontinuity of intensity values at the line of fusion which
appear as a distinct line (also called a seam). Visual inspection
or automated analysis of the mosaic image can reveal the presence
or absence of seam. If the seam is present, then further correction
is necessary for its removal.
[0028] Should the line of fusion in the stitched image fail to meet
the predetermined criteria, the mosaic image can be corrected.
According to an embodiment of the disclosure, the stitched image
can be corrected by defining a window in the stitched image which
contains the line of fusion. Referring to image 430, window 435
(shown in broken lines) surrounds line of fusion 425. Within window
435 a randomly-selected pixel can be selected and its corresponding
pixels in each of first sub-image 410 and second sub-image 420
identified. A corresponding pixel is one that appeared in the
original sub-image(s). Referring to the embodiment of FIG. 4, the
intensity value associated with each of the corresponding pixels
can be used to determine a weighted sum intensity value for the
randomly-selected pixel within window 435. Once the weighted sum
intensity value has been determined, the intensity value of the
randomly-selected pixel can be replaced therewith in order to
correct the stitched image 430.
[0029] According to another embodiment of the disclosure, the
process of correcting the stitched image may include determining
the weighted sum intensity value for all pixels within line of
fusion 425, window 435 or overlapping area 415 and replacing each
actual pixel intensity with the weighted sum intensity value
determined based on the pixel's corresponding pixels as appearing
in each original sub-image. Referring to FIG. 4, mosaic image 440
illustrates the corrected version of mosaic image 430. The mosaic
image 440 provides an image of a sample at one wavelength. To
obtain a comprehensive mosaic image of the sample, the process can
be repeated for images having different wavelengths and the mosaic
images can be combined to form a comprehensive mosaic image of the
sample.
[0030] While the disclosure has been described in relation to
exemplary embodiments and specific examples, it should be noted
that the principles disclosed herein are not limited to the
enumerated embodiments and include any variation, permutation and
modification thereto.
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